Question

[3] A nutrition expert is examining a weight-loss program to evaluate its effectiveness.

Ten subjects are randomly selected for the investigation, the data are as follows:

Subject 1 2 3 4 5 6 7 8 9 10

Initial Weight 180 142 126 138 175 205 116 142 157 136

Final Weight 165 138 128 136 170 197 115 128 144 130

Is there evidence of significant weight loss?

Run the appropriate test at 5% level significance.

USE R AND SHOW CODES

Answer 1

Let , X=Initial Weight and Y=Final Weight

Let ,

Hypothesis : Vs

By using R : The output is given by ,

> t.test(X,Y,mu=0,,paired=T,conf.level=0.95)

Paired t-test

data: X and Y
t = 3.5887, df = 9, p-value = 0.002925
alternative hypothesis: true difference in means is greater than 0
95 percent confidence interval:
3.228755 Inf
sample estimates:
mean of the differences
6.6

Decision : Here , p-value=0.002925 <

Therefore , reject Ho

Conclusion : Hence , there is sufficient evidence of significant weight loss.